This invention relates to a device used in chemical process towers or columns to collect liquid trickling down the interior wall of the tower and then orient it away from the wall into some type of tower internal. Examples of such towers or columns are distillation towers, absorption towers, and extraction towers. Examples of such tower internals are liquid distributors, liquid redistributors, and liquid side draw collectors. Most chemical process columns and towers are cylindrical in shape and stand in an upright position, or more precisely most of these towers are designed to be vertically oriented, right circular cylindrical sections.
Often within such towers there is liquid flowing downwardly, and it is usually highly desireable to have this liquid distributed in a uniform pattern across a given imaginary horizontal cross-section of the tower. However, it is known among those skilled in the art that the downflowing liquid migrates toward the internal side walls of the tower to which it adheres and continues its downward flow. Thus the further you go down a tower in which this migration is unchecked, the more liquid there is flowing downwardly along the tower walls and the less uniform distribution of this liquid across an imaginary horizontal tower cross-section. This problem has been found to be particularly acute in instances where the downward liquid flow is at very low flowrates; e.g., less than about 1.0 gallon per minute per square foot of tower cross-section, taken across an imaginary horizontal cross-sectional plane of the tower.
The prior art teaches many tower internals to redirect and/or collect this liquid flowing downwardly along the internal tower wall, but they all suffer from the same fundamental problem. This problem is that although the towers are specified as being cylindrical with a given internal diameter, and accordingly the internals designed to fit them are specified to have the same cylindrical diameter, these towers and internals are never a geometrical true cylinder. In their construction, aberrations, albeit small, appear in these towers which prevent them from being perfectly round. This too has long been known by those working with such towers as is manifest by the several means and methods they have gone about correcting these aberrations.
These correcting means have centered principally around two approaches, one being to weld or bolt the tower internals in place and then running a weld bead between the outer periphery of the internal and the inner periphery of the tower wall to form a leak-proof seal therein between. Of course, unwelding such an internal from the tower wall is a very tedious task for those who have to crawl into the tower to make some sort of tower modification requiring tower internal modification.
The other principal approach used to try to provide leak proof seals has been to provide gasketing materials between the out-of-round tower internal and tower wall. But even these gasketing protection procedures allow some leakage down the tower wall which is especially noticeable at very low liquid flowrates when such flows are desired to be maintained at a uniform distribution across the towers, or when the liquid is desired to be removed from the tower at some level within the tower.
These shortcomings and others have been overcome by the present invention. This invention is a liquid wall flow collector which is easy to install and easy to remove from the tower for maintenance of the internal into which it is directing the wall liquid. It provides an excellent seal to the tower wall whether the interior of the tower wall is perfectly round or not. It provides its own friction joint against the tower wall to provide its own support within the tower without requiring the presence of bolting or welding to the tower wall. Its position within the tower relative to the tower internal can be easily adjusted.
These advantages and others can be observed in the further description of the invention.